Carbohydrate Deficient Transferrin, Adult, Serum
An indicator of chronic alcohol abuse
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Chronic alcoholism causes a transient change in the glycosylation pattern of transferrin where the relative amounts of disialo- and asialotransferrin (carbohydrate deficient transferrin: CDT) are increased over the amount of normally glycosylated tetrasialotransferrin. This recognition led to the use of CDT in serum as marker for chronic alcohol abuse. CDT typically normalizes within several weeks of abstinence of alcohol use. However, it is important to recognize that there are other causes of abnormal CDT levels, which include congenital disorders of glycosylation and other genetic and non-genetic causes of acute or chronic liver disease.
CDT testing alone is not recommended for general screening for alcoholism; however, when combined with other methods (ie, gamma-glutamyltransferase, mean corpuscular volume, patient self-reporting) clinicians can expect to identify 90% or more of patients who consume a large amount of alcohol.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
< or =0.10
Patients with chronic alcoholism may develop abnormally glycosylated transferrin isoforms (ie, carbohydrate deficient transferring: CDT >0.12). CDT results from 0.11 to 0.12 are considered indeterminate.
Patients with liver disease due to genetic or nongenetic causes may also have abnormal results.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This assay has not been fully validated for the investigation of alcoholism.
Carbohydrate deficient transferring (CDT) testing alone is not recommended for general screening for alcoholism.
The abnormal transferrin isoform pattern in patients with chronic alcoholism is similar to that observed in congenital disorders of glycosylation (CDGs). However, unlike most patients with CDG, the relative amount of mono-glycosylated transferrin is much lower. Other conditions such as hereditary fructose intolerance, galactosemia, and liver disease may result in increased levels of CDT. In addition, pre-analytical variables such as bacterial contamination may cause falsely elevated CDT values. Several factors may cause variability in CDT analysis, including: ethnicity, gender, pregnancy, body mass index, smoking, blood pressure, iron metabolism, drug interactions, chronic medical illness.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Delanghe JR, De Buyzere ML: Carbohydrate deficient transferrin and forensic medicine. Clin Chim Acta 2009;406:1-7
2. Fleming MF, Anton RF, Spies CD: A review of genetic, biological, pharmacological, and clinical factors that affect carbohydrate-deficient transferrin levels. Alcohol Clin Exp Res 2004;28(9):1347-1355
3. Salaspuro M: Carbohydrate-deficient transferrin as compared to other markers of alcoholism: a systematic review. Alcohol 1999;19:261-271
4. Stibler H: Carbohydrate-deficient transferring in serum: a new marker of potentially harmful alcohol consumption reviewed. Clin Chem 1991;37:2029-2037
5. Torrente MP, Freeman WM, Vrana KE: Protein biomarkers of alcohol abuse. Expert Rev Proteomics 2012;9(4):425-436